I have a'LazyGlide <img src="http://jsramsbottom.co.uk/bbs/e/icon_wink.gif" alt="Wink" width="15" height="15"><!--graemlin:-->' HW80 in .20 and was lucky to find that with the restricted choice of pellets available (in comparison to .22 and .177) that it shoots Bisley Superfield very well. Bit of a gamble that paid off in my case.
Can't say how more effective it is over .22/.177 when used in pest control as I do not hunt.
<img src="http://jsramsbottom.co.uk/bbs/e/icon_cool.gif" alt="Cool" width="15" height="15"><!--graemlin:-->